<!-- 圣杯布局 -->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div {
      text-align: center;
    }

    #header {
      background-color: rgb(197, 32, 32);
    }

    #content {
      padding-left: 300px;
      padding-right: 200px;
    }

    #content #center{
      width: 100%;
      background-color: bisque;
    }

    #content #left {
      background-color: orange;
      width: 300px;
      margin-left:-100%;
      position: relative;
      right: 300px;
    }

    #content #right {
      background-color: green;
      width: 200px;
      margin-right: -200px;
    }

    #footer {
      background-color: rgb(197, 32, 32);
      clear: both;
    }

    #content .colum {
      float: left;
    }

  </style>
</head>
<body>
  <h1>实现圣杯布局</h1>
  <div id="header">header</div>
  <div id="content">
    <div class="colum" id="center">center</div>
    <div class="colum" id="left">left</div>
    <div class="colum" id="right">right</div>
  </div>
  <div id="footer">footer</div>
</body>
</html>